JP4112891B2 - In-reactor transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention relates to a mobile device and a reactor suitable for performing maintenance work such as inspection, inspection or cleaning of a reactor pressure vessel or a reactor internal structure in, for example, a boiling water reactor (hereinafter referred to as BWR). It relates to the working method.
[0002]
[Prior art]
Equipment such as an in-reactor structure installed in a reactor pressure vessel in the BWR is arranged as shown in FIG. FIG. 4 is a partial schematic view of the main part. In FIG. 4, reference numeral 1 partially indicates a lower mirror, and the lower mirror 1 is a lower mirror opening of a cylindrical reactor pressure vessel. Is to block. A plurality of stub tubes 2 are attached to the lower mirror 1, and a control rod drive mechanism (hereinafter referred to as CRD) housing 3 is welded through the stub tubes 2. A control rod guide tube 4 is installed at the tip of the CRD housing 3. A CRD (not shown) is installed in the CRD housing 3.
[0003]
The control rod guide tube 4 projects through the hole 6 of the core support plate 5 and is supported by the core support plate 5. A fuel support fitting 7 is removably provided in the upper opening of the control rod guide tube 4. Yes. The control rod guide tube 4 and the fuel support fitting 7 are fixed by inserting respective lugs into positioning pins (not shown) provided on the core support plate 5.
[0004]
A control rod 8 having a horizontal cross section is provided in the control rod guide tube 4 so as to be movable up and down. The lower end of the control rod 8 is connected to the upper end of the CRD, and the fuel assembly 9 extends from the upper end of the control rod guide tube 4. The control rod 8 can be inserted into the gap between them.
[0005]
The upper portion of the fuel support bracket 7 supports the lower tie plate of the four fuel assemblies 9, and the upper portion of the fuel assembly 9 is supported by the upper lattice plate 10. In FIG. 4, reference numeral 11 is-core housing attached to the lower mirror 1, 12 in the in-core guide tube, it is provided between the up furnace center support plate 5.
[0006]
By the way, when performing maintenance work such as cleaning, inspection and inspection of the reactor pressure vessel lower mirror 1, as described above, the lower mirror 1 is provided with a number of stub tubes 2 and in-core housings 11. Is an inclined curved surface, and it is difficult to work using a traveling carriage equipped with various working devices.
[0007]
Therefore, conventionally, when performing the above maintenance work, various work devices are attached to the end of the long pole, and an operator suspends the pole from above the reactor pressure vessel, and the upper lattice plate 10 and the core support plate 5 are suspended. An operator manually performs the operation while passing through the hole 6.
[0008]
Further, a manipulator for transferring and positioning various working devices and a feeding mechanism are incorporated in a long casing through which the hole 6 of the core support plate 5 can pass, and this device is mounted on the core support plate 5 and the CRD housing 3. It is installed on top and performs various tasks.
[0009]
[Problems to be solved by the invention]
However, when the various operations in the reactor pressure vessel are performed manually by workers, the long pole must be operated at a position of about 25 m underwater, so the workability is very inferior and time There is a problem that requires labor.
[0010]
Further, when a long working device through which the hole 6 of the core support plate 5 can pass is installed at the bottom of the furnace, the workable range is limited from one installation position, and the installation position is changed. In this case, a long and large device must pass through the hole 6 of the core support plate 5 and the upper lattice plate 10 to lift the entire device on the upper lattice plate 10 and then move to the next installation position. This also has a problem that requires time and labor.
The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a moving apparatus and an in-reactor operation method capable of efficiently performing maintenance work.
[0011]
[Means for Solving the Problems]
The invention according to claim 1, and connected to the first single-row crawler module, a second single-row crawler module, the first and second single-row crawler module to respective longitudinal, perpendicular 3 a rotatable joint mechanism around axis, the connection angle of the first and second single-row crawler module by operating the vertical axis joint mechanism consists gear provided on the vertical axis joint mechanism of the joint mechanism The rotary drive mechanism to change, the motor used as the drive source of this rotary drive mechanism, and the float mounted in the said 1st and 2nd single row crawler module were provided.
[0012]
The invention according to claim 2 is characterized in that the inside of the float is filled with gas, is reduced by an external pressure, and is expanded by an internal pressure .
The invention according to claim 3 is characterized in that an image sensor and a pan head that is rotatable in the pan direction and the tilt direction are mounted on the first single-row crawler module .
[0013]
The invention according to claim 4 is characterized in that a brush and a suction cleaning device having a suction nozzle are mounted on the single row crawler module .
The invention according to claim 5 is characterized in that an ultrasonic probe for following a region to be inspected is mounted on the single row crawler module .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of a mobile device according to the present invention will be described with reference to FIG.
FIG. 1 is a front view of a moving apparatus according to the present embodiment. In FIG. 1, reference numeral 13 denotes a first single-row crawler module, and 14 denotes a second single-row crawler module.
[0017]
The first single row crawler module 13 and the second single row crawler module 14 are connected to each other in the longitudinal direction by a rotatable joint mechanism 15. The rotatable joint mechanism 15 includes a turning axis rotating joint 16, a horizontal axis rotating joint 17, and a vertical axis rotating joint 18, and rotates around three orthogonal axes. Then, a rotation drive mechanism is attached to the vertical axis rotary joint 18. Thereby, the 1st single row crawler module 13 and the 2nd single row crawler module 14 can be rotated relatively on a horizontal surface, and the whole attitude | position can be changed.
[0018]
That is, a large-diameter gear 19 serving as a rotational drive mechanism, a small-diameter gear 20 that meshes with the large-diameter gear 19, and a rotary motor 21 are attached to the vertical shaft rotary joint 18. The small-diameter gear 20 is attached to the rotation shaft of the rotary motor 21. The rotary motor 21 is mounted on the upper plate 22 of the second single row crawler module 14 via an attachment member 23.
[0019]
A pan head 25 is mounted on the upper plate 24 of the first single-row crawler module 13, and an illuminated CCD camera (image sensor) 26 is rotatably attached to the pan head 25. The pan head 25 is for changing the direction of the illuminated CCD camera 26 for visual inspection in the pan (left and right) direction and the tilt (up and down) direction.
[0020]
According to the present embodiment, two single row crawler modules 13 and 14 are connected in the longitudinal direction by joint mechanisms 15 that are rotatable around three orthogonal axes, and each crawler module 13 and 14 is connected to joint mechanism 15. It is possible to move freely by rotating on a plane and changing the overall posture. Also, each single row crawler module 13, 14 is a single row and does not take a width, so it can be configured to be elongated, and when passing through a narrow part, it can be transformed into a dogleg shape, It has an advantageous shape.
[0021]
Furthermore, since the motor for driving the crawler module can be disposed in the rotating crawler belt 27, the center of gravity of the crawler module can be lowered, and the lower mirror 1 having an inclined curved surface on the lower surface of the reactor pressure vessel can also fall over. Therefore, a sufficient driving force can be ensured.
[0022]
Next, a first embodiment of the in-reactor working method according to the present invention will be described with reference to FIG. 2, FIG. 3 and FIG.
The present embodiment is an example in which maintenance work is performed on the bottom of the reactor pressure vessel by moving on the lower mirror 1 in the reactor pressure vessel using the moving device described in FIG.
[0023]
2 and 3 show a state in which the in-reactor moving apparatus having the structure shown in FIG. 1 moves, that is, moves and moves in the narrow portion around the stub tube 2 and the in-core housing 11 on the inner mirror 1 of the reactor pressure vessel. 2 and 3 are schematic top views as seen from the direction of arrows AA in FIG.
[0024]
In the present embodiment, first, in FIG. 4, after removing the fuel assembly 9, the fuel support 7, the control rod 8, and the control rod guide tube 4, the in-reactor moving device is connected to the upper lattice plate from above the reactor pressure vessel. 10. Pass through the core support plate 5 and place on the lower mirror 1. In this case, if the movement is only forward and backward, the first and second single-row crawler modules 13 and 14 can be driven and moved while the crawler modules 13 and 14 are relatively in series.
[0025]
However, as shown in FIG. 2, when the stub tube 2 is wrapped around the lower mirror 1, the rotary motor 21 is rotated to change the relative orientation of the single-row crawler modules 13 and 14, so that the entire moving device becomes a square shape. Control to deform. When the crawler modules 13 and 14 are driven in this state, the moving device can move in the direction of the arrow in FIG. Also, as shown in FIG. 3, when the in- core housing 11 is swung around while being moved, if the entire moving device is controlled so as to be deformed into a dogleg shape with the rotatable joint mechanism 15 as the central axis, the movement can be achieved. Becomes easy.
[0026]
Further, in this embodiment, by mounting a CCD camera 26 with illumination for visual observation, the situation on the lower mirror 1, the welded portion between the reactor pressure vessel and the stub tube 2, the reactor pressure vessel and the in-core housing 11 Visual inspection of the weld can be performed. Further, when a suction cleaning device (not shown) having a brush or a suction nozzle is mounted, the suction cleaning operation can be performed on the lower mirror 1. In addition, an ultrasonic probe is mounted, and this ultrasonic probe is welded while following the inspection target site such as the reactor pressure vessel and the stub tube 2 or the reactor pressure vessel and the in-core housing 11. Ultrasonic flaw detection work can be performed.
[0027]
According to this embodiment, since the moving device is small and can be self-propelled, it can pass through the narrow portion between the stub tubes or between the stub tube and the in-core housing on the reactor pressure vessel inner mirror. In addition, since the center of gravity is configured to be low, stable movement performance can be ensured without falling even on an inclined curved surface or uneven surface. Therefore, the mobile device can be installed at one location on the lower mirror 1 to perform maintenance work such as extensive cleaning, inspection, inspection, etc., and the installation position can be changed in a short time. Cleaning, inspection, inspection The maintenance work of the bottom of the reactor pressure vessel can be efficiently performed.
[0028]
Next, a second embodiment of the moving apparatus and the in-reactor working method according to the present invention will be described.
This embodiment is different from the first embodiment in that floats (not shown) are mounted on the first and second crawler modules 13 and 14. A float is a kind of “floating” filled with a gas such as air, and supplies buoyancy to the entire moving device. With this float, when the position of the center of gravity of the in-reactor moving apparatus is increased, it is possible to prevent the fall during traveling on the inclined surface or the uneven surface of the lower mirror 1. Therefore, a stable driving force can be ensured even on an inclined surface or an uneven surface.
[0029]
Moreover, the float mounted in the 1st and 2nd crawler modules 13 and 14 is comprised by shrinking | reducing by the water pressure (external pressure) in water, and applying air pressure (internal pressure) so that expansion | swelling is possible. For example, it can also be constituted by a watertight bellows provided with a guide that keeps the shape when expanded. Then, control is performed so that an appropriate amount of air pressure is applied to the float by a pump (not shown).
[0030]
The lower mirror 1 is located about 25 m below the water surface, and the float is usually reduced by water pressure. Then, the air pressure is applied only when the moving device falls on the inclined surface to expand the float, and the moving device is returned by buoyancy to bring the crawler drive surface into contact with the lower mirror 1. Therefore, it is not necessary to reduce the underwater weight due to the buoyancy of the float, so that the driving force of the crawler module can be secured to the maximum.
[0031]
【The invention's effect】
According to the present invention, it is possible to efficiently perform maintenance work in a narrow part.
[Brief description of the drawings]
FIG. 1 is a front view for explaining a first embodiment of a moving apparatus according to the present invention.
FIG. 2 is a top view seen from the direction of arrows AA in FIG. 4 for explaining a first example of the traveling state of the mobile device according to the present invention.
3 is a top view seen from a direction different from the direction of arrows AA in FIG. 4 for explaining a second example as in FIG. 2;
FIG. 4 is a perspective view showing an arrangement of structures in a reactor pressure vessel of a BWR.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Lower mirror, 2 ... Stub tube, 3 ... CRD housing, 4 ... Control rod guide tube, 5 ... Core support plate, 6 holes, 7 ... Fuel support metal fitting, 8 ... Control rod, 9 ... Fuel assembly, 10 ... Upper lattice plate, 11 ... in-core housing, 12 ... in-core guide tube, 13 ... first single row crawler module, 14 ... second single row crawler module, 15 ... joint mechanism, 16 ... swivel rotary joint, 17 ... horizontal Shaft rotary joint, 18 ... Vertical axis rotary joint, 19 ... Large diameter gear, 20 ... Small diameter gear, 21 ... Rotary motor, 22 ... Upper plate, 23 ... Mounting member, 24 ... Upper plate, 25 ... Head, 26 ... Illumination CCD camera (image sensor).

Claims (5)

A first single-row crawler module, a second single-row crawler module, the first and second single-row crawler module connected to respective longitudinal, rotatable joint mechanism to 3 about the axis orthogonal When, a rotation drive mechanism that vertically axis joint mechanism consists gear provided on operate this vertical axis joint mechanism varying said first and connection angle of the second single-row crawler module of the joint mechanism, the An in-reactor moving apparatus comprising: a motor serving as a driving source of a rotation driving mechanism; and a float mounted on the first and second single row crawler modules . 2. The in- reactor transfer apparatus according to claim 1 , wherein the float is filled with gas, contracted by an external pressure, and expanded by an internal pressure . An image sensor of the image sensor Toko pan direction and reactor mobile device according to claim 1, wherein the rotatable pan head in the tilt direction, characterized in that mounted on the first single-row crawler module. The in-reactor moving apparatus according to claim 1 , wherein a brush and a suction cleaning apparatus having a suction nozzle are mounted on the single row crawler module . 2. The in-reactor moving apparatus according to claim 1, wherein an ultrasonic probe for copying the inspection target part is mounted on the single row crawler module .

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